MESOSCALE DISCUSSION 0410
NWS STORM PREDICTION CENTER NORMAN OK
0622 PM CDT SAT APR 26 2014
AREAS AFFECTED...PORTIONS OF WEST CENTRAL AND WRN NORTH TX INTO SWRN
OK
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 262322Z - 270045Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...PORTIONS OF WEST CENTRAL AND WRN NORTH TX INTO SWRN OK ARE
BEING MONITORED FOR POTENTIAL WATCH ISSUANCE. A TSTM HAD DEVELOPED
IN FISHER COUNTY AND ADDITIONAL STORMS WILL BE POSSIBLE WITHIN A N-S
ORIENTED CORRIDOR...GENERALLY 35-45 MILES EITHER SIDE OF A LINE FROM
35 S ABI TO 20 N LTS....WITH LARGE HAIL AND DAMAGING WINDS BEING THE
INITIAL PRIMARY THREATS.
DISCUSSION...TRENDS IN VISIBLE SATELLITE/RADAR IMAGERY CONTINUED TO
SHOW TWO DRY LINES OVER THE WRN PORTION OF THE SRN PLAINS. ONE
EXTENDED FROM ALONG THE WRN OK/TX PANHANDLE BORDER SWWD TO 25 N MAF
AND THEN SWD TO 25 WSW OF SANDERSON TX. A SECOND DRY LINE WAS
LOCATED TO THE EAST OF THE FIRST ONE AND WAS RETREATING SLOWLY WWD
PER TRENDS IN RADAR IMAGERY INVOF OF ABI NWD INTO FAR SWRN OK. THIS
SECOND DRY LINE APPEARS TO BE DELINEATING HIGHER MOISTURE RETURN
WITH SURFACE DEWPOINTS IN THE MID-UPPER 50S TO ITS EAST COUPLED WITH
SURFACE TEMPERATURES INTO THE LOWER-MID 90S ALONG THIS DRY LINE
FEATURE. THESE OBSERVED THERMODYNAMICS HAVE AIDED IN WEAKENING OF
SURFACE-BASED INHIBITION THAT WAS PRESENT EARLIER.
TRENDS IN LOW-LEVEL WINDS DURING THE MID-LATE AFTERNOON FROM EXTREME
SWRN OK TO SJT HAVE BACKED TO SLY...WHILE WINDS AT THE SAME LEVEL
FROM AMA-MAF WERE WSWLY INDICATING A ZONE OF LOW-LEVEL CONFLUENCE
PRIMARILY ALONG THE SECOND DRY LINE. IT IS ALONG THIS BOUNDARY WITH
A WEAKENED CAP THAT SATELLITE AND RADAR IMAGERY SHOWED TOWERING CU
AND A COUPLE CB/S. A COUPLE OF LIGHTNING STRIKES WERE DETECTED IN
FISHER COUNTY TX AROUND 2245Z. THE INCREASE IN LOW-LEVEL
CONVERGENCE APPEARS TO BE IN RESPONSE TO AN APPARENT MIDLEVEL
IMPULSE OR JET STREAK TRACKING NEWD THROUGH WEST CENTRAL TX AT THIS
TIME. ASCENT WITH THIS FEATURE IS ALSO LIKELY AIDING IN THE
INCREASE IN CONVECTIVE DEVELOPMENT...MAINLY ALONG THE DRY LINE
WITHIN THE DISCUSSION AREA. FURTHER W/NWWD MOISTURE RETURN INTO
THIS BOUNDARY INTO THE EARLY EVENING SHOULD BOOST INSTABILITY FOR
MORE ROBUST UPDRAFT POTENTIAL. EFFECTIVE BULK SHEAR OF 30-35 KT
ORIENTED ACROSS THE DRY LINE WILL SUPPORT DISCRETE STORMS...WITH A
STEEP LAPSE RATE ENVIRONMENT FAVORING A THREAT FOR LARGE HAIL.
MEANWHILE...LARGE SURFACE TEMP-DEWPOINT SPREADS /35-40 DEGREES/ TEND
TO RESULT IN LP SUPERCELLS ENHANCING A THREAT FOR DAMAGING WIND
GUSTS. IF TSTM COVERAGE AND/OR INTENSITY INCREASES
SUFFICIENTLY...THEN A WATCH MAY BE NEEDED.
..PETERS/HART.. 04/26/2014
ATTN...WFO...FWD...OUN...SJT...LUB...
LAT...LON 32330052 33410017 34729990 35029959 34839873 33879857
32359870 31989919 31600041 32330052